Preheat your oven to 325°F (160°C). In a small bowl, stir together graham cracker crumbs and granulated sugar. Drizzle in melted butter and mix until combined. Press firmly into the bottom and 1/2-1 inch up the sides of a 9-inch springform pan. Bake for 10-12 minutes until dry, then let cool completely.

Reduce your oven temperature to 275°F (135°C). In a large bowl, whip softened cream cheese until smooth and fluffy. Add Greek yogurt or sour cream and whip to combine. Add granulated sugar, vanilla extract, and eggs; whip until smooth, avoiding over-mixing. Pour the cheesecake batter into the cooled crust.

In a medium bowl, toss peeled, sliced apples with granulated sugar and cinnamon. Spoon evenly over the cheesecake batter.

In a small bowl, combine flour, rolled oats, brown sugar, and cinnamon. Drizzle melted butter over the mixture and stir until it forms crumbles. Sprinkle evenly over the apple layer.

Place the springform pan on a baking sheet and bake at 275°F (135°C) for 1 1/2 to 2 hours, until an instant-read thermometer reads 150°F (66°C). Let sit in the warm oven for one hour after turning it off.

Remove the cheesecake, run a knife around the edges, let cool completely on a wire rack for 3-4 hours, then chill overnight.

Before serving, drizzle with salted caramel sauce. Slice with a sharp, warm knife.